286 LIFE HISTOEIES OP NOETH AMEEIOAN BIEDS. 



The average measurement of thirty-two eggs in the United States National 

 Museum collection is 21.51 by 16.10 millimetres, or about 0.85 by 0.63 inch. 

 The largest egg of the series measures 23.11 by 17.27 millimetres, or 0.91 by 

 0.68 inch; the smallest, 20.32 by 15.24 millimetres, or 0.80 by 0.60 inch. 



The type specimen. No. 23891 (PI. 2, Fig. 15), from a set of three eggs 

 taken by Mr. Gale, near Gold Hill, Boulder County, Colorado, on July 3, 1889, 

 represents one of the richer-colored eggs, while No. 25685 (PL 2, Fig. 16), from 

 a set of three, Ralph collection, also from Colorado, taken June 16, 1892, shows a 

 paler-colored example; they also show the difference in size. 



io6. Contopus pertinax Cabanis. 



COUES'S FLYCATCHEE. 



Myiarchus pertinax Lichtenstein, Komenclator Mueso Beroliueusis, 1854, 16 (nomen 



nudum). 

 Conto}) us pertinax Cabanis, Museum Heiueauum, II, Sept. 30, 1859, 72. 

 (B— 254, E 319, C 381, U 460.) 



Geographical range: Higlihinds of Guatemala and Mexico; uortk to Arizona 

 and southwestern New Mexico. Accidental iu Colorado. 



The breeding range of Coues's Flycatcher is eoextensive with its geo- 

 graphical distribution in the United States, where it is only a summer visitor. It 

 was added to our avifauna by Dr. Elliott Coues, who took a specimen near 

 Fort Whipple, Arizona, on August 20, 1864; and since then it has been found 

 to be generally distributed throughout the mountains of the southern half of 

 Arizona and southwestern New Mexico, although nowhere very common. 



The best account of its general habits is that of Mr. H. W. Henshaw, who 

 says: ''In 1873 I obtained a pair of old birds, which were accompanied bj 

 several young, in the White Mountains, near Camp Apache, and, not meeting 

 with it elsewhere, supposed it to be rare. Such, however, proves not to be the 

 case, as the past season it was found to be one of the most numerous and char- 

 acteristic of the Flycatcher tribe, being seen everywhere in the mountainous 

 districts from Camp Apache to the border line. 



" In general appearance as well as habits it is quite similar to the Olive- 

 sided Flycatcher, and shows the same proclivities for inhabiting the pineries, 

 often on the edge of an opening, or where the country is diversified and cut 

 up by rocky ravines and the pines are interspersed with oak woods. In such 

 places tliB species is sure to be present, and may be seen circling about the 

 high pine stubs or descending to the lower trees, as the oaks, and launching 

 itself out from the branches in vigorous pursuit of flies or beetles, which it 

 hunts with the greatest energy and perseverance. The notes are loud and very 

 forcibly given, possessing the same character as the call of the Olive-sided 

 Flycatcher, but are readily distinguishable. They resemble the syllables 

 'pe-wee-ee,' great emphasis being laid on the middle syllable, while the last 

 is quite prolonged and in a slightly raised key. Each pair apparently takes 



